1. Field of the Invention
The present invention relates to an organic electroluminescent device and a driving method thereof. Particularly, the present invention relates to the organic electroluminescent device capable of preventing screen pause phenomenon occurring when the brightness of pixels is changed, and a driving method thereof.
2. Description of the Related Art
An organic electroluminescent device is a device emitting a light having a predetermined wavelength when a certain voltage is applied thereto.
FIG. 1 is a view showing an organic electroluminescent device in the art.
In FIG. 1, the organic electroluminescent device in the art includes a panel 100, a scan driving circuit 110, a data storage part 120, and a data driving circuit 130.
The panel 100 includes a plurality of pixels E11 to E14, E21 to,E24, E31 to E34, and E41 to E44 formed on an emitting area crossing over data lines D1 to D4 and scan lines S1 to S4. (It is understood that any reference to pixels E11 to E44 in FIG. 1 corresponds to pixels E11 to E14, E21 to E24, E31 to E34, and E41 to E44).
Each of the pixels E11 to E44 is formed with an anode electrode layer, an organic layer and a cathode electrode layer, and emits a light having a certain wavelength when a positive voltage is applied to the anode electrode layer, and a negative voltage is applied to the cathode electrode layer.
The scan driving circuit 110 provides scan signals to each of the scan lines S1 to S4.
The data storage part 120 stores display data and brightness control data inputted from outside. In detail, according to an input order of display data and brightness control data, the data storage part 120 stores the display data and brightness control data to a latch in sequence by using a shift resister (not shown).
The display data is RGB data having the information of colors that the pixels emit.
The brightness control data controls brightness of the pixels E11 to E44. In detail, the brightness control data sets a maximum brightness level that the pixels E11 to E44 can emit, for each of red, green and blue pixels.
The data driving circuit 130 provides a data current according to the display data provided from the data storage part 120 to the data lines D1 to D4. Here, the data current is synchronized with the scan signals.
FIG. 2 is a timing diagram showing the display data signal and the brightness control data signal provided to the data driving circuit of FIG. 1.
When the display data is inputted, the organic electroluminescent device starts to emit a light accordingly.
In FIG. 2, the organic electroluminescent device continues to emit a light by applying the data signal and the scan signals to each of the pixels E11 to E44 from the time S that the display data is inputted. In case the brightness of the pixels E11 to E44 is changed while the light-emitting is continued, the brightness control data according to the changed brightness is inputted to the data storage part 120.
At this time, the display data and the brightness control data are inputted through only one line, and so the input of the display data is discontinued at the section (A) into which the brightness control data (section A) is inputted.
Then, a phenomenon that the light-emitting is temporarily discontinued is occurred at the section A. That is, the screen is paused temporarily. This screen-pause phenomenon is occurred every time the brightness control data is changed.
Thus, there has been a need to develop a device that can prevent the screen-pause phenomenon of the organic electroluminescent device.